Organoclay compositions for gelling unsaturated polyester resin systems

ABSTRACT

An organoclay composition for gelling unsaturated polyester resin/monomer systems comprising a mineral clay mixture which has been treated with an alkyl quaternary ammonium compound. The mineral clay mixture comprises two components: mineral clay (a) comprising greater than 50 wt. %, based on the weight of the mineral clay mixture, of a mineral clay selected from the group consisting of sepiolite, palygorskite and mixtures of sepiolite and palygorskite; and mineral clay (b) comprising less than 50 wt. %, based on the weight of the mineral clay mixture, of a smectite.

This application is a 371 of PCT/US96/11709 filed on Nov. 7, 1996 andclaims the benefit of U.S. Provisional Application No. 60/006,310, filedon Nov. 7, 1995.

FIELD OF THE INVENTION

This invention relates to organoclay compositions, which are readilydispersible in unsaturated polyester resin systems and are adapted toconfer thixotropic properties to such systems.

BACKGROUND OF THE INVENTION

Fumed silica is currently used as a direct additive for rheologicalcontrol of unsaturated polyester resin systems. Organoclays, typicallyrepresenting the reaction product of a smectite-type clay with aquaternary ammonium compound, have also been used for these purposes,but normally require a pregel of the organoclay in styrene for properviscosity development prior to addition to the resin system. This isdiscussed in numerous prior art patents, e.g. U.S. Pat. Nos. 4,473,675and 4,240,951.

Various producers of organoclays have had limited success preparingdirect add organoclays which do not require a pregel with an unsaturatedpolyester resin/styrene system, see for example U.S. Pat. No. 4,753,974.By and large, however, these prior efforts have not produced a productwhich is broadly competitive with fumed silica.

OBJECT OF THE INVENTION

Pursuant to the foregoing, it may be regarded as an object of thepresent invention, to provide an organoclay composition which can bestirred directly into a solution of an unsaturated polyester resin in anappropriate monomer such as styrene and which will confer thixotropicgelling properties on such system.

SUMMARY OF THE INVENTION

Now in accordance with the present invention, it has unexpectedly beendiscovered that combinations of certain clay minerals may be reactedwith quaternary ammonium compounds to provide additives which willreadily disperse and provide the required gelling properties forunsaturated polyester resin systems.

DETAILED DESCRIPTION OF THE INVENTION

The organoclay compositions of the invention which are useful forgelling unsaturated polyester resin systems comprise mineral claymixtures which have been treated with alkyl quaternary ammoniumcompounds. Such mineral clay mixtures in turn comprise:

mineral clay (a) comprising greater than 50 wt. %, based on the weightof the mineral clay mixture, of a mineral clay selected from the groupconsisting of sepiolite, palygorskite and mixtures of sepiolite andpalygorskite; and

mineral clay (b) comprising less than 50 wt. %, based on the weight ofthe mineral clay mixture, of a smectite. Preferably, mineral clay (a) ispresent in an amount of 60 to 95 wt. %, especially 70 to 90 wt. %, basedon the weight of the mineral clay mixture.

Of the two mentioned phyllosilicates, sepiolite is preferred for use inthe invention. Both sepiolite and palygorskite are included in thephyllosilicates because they contain a continuous two-dimensionaltetrahedral sheet of composition T₂O₅ (T═Si, Al, Be, . . . ) but theydiffer from the other layer silicates in lacking continuous octahedralsheets. Further details of the structures of these minerals, includingthe structural distinctions between the two, may be found in B. F. Jonesand E. Galan “Sepiolite and Palygorskite”, chapter 16 of HydrousPhyllosilicates, Reviews in Mineralogy. Volume 19, (MineralogicalSociety of America, Washington, D.C., 1988).

Preferably, the smectite is a natural or synthetic clay mineral selectedfrom the group consisting of hectorite, montmorillonite, bentonite,beidelite, saponite, stevensite and mixtures thereof. A particularlypreferred choice of the smectite is hectorite.

In a preferable procedure for preparing the organoclay composition, thesepiolite and/or palygorskite is crushed, ground, slurried in water andscreened to remove grit and other impurities. The smectite mineral issubjected to a similar regimen. Each of the component minerals is thensubjected as a dilute (1 to 6% solids) aqueous slurry to high shearingin a suitable mill. Most preferred for use in this shearing step is ahomogenizing mill of the type wherein high speed fluid shear of theslurry is effected by passing the slurry at high velocities through anarrow gap, across which a high pressure differential is maintained.This type of action can e.g. be effected in the well-known Manton-Gaulin“MG”) mill, which device is sometimes referred to as the “Gaulinhomogenizer”. Reference may be made to commonly assigned U.S. Pat. Nos.4,664,842 and 5,110,501 for further details of such mill. The conditionsfor use of the MG mill may in the present instance be substantially asin the said patents; e.g. the said pressure differential across the gapis preferably in the range of from 70,300 to 562,400 g/cm² with 140,600to 351,550 g/cm² being more typical in representative operations.Depending upon the specifics of the equipment, pressures higher than562,400 g/cm² can readily be used. The slurry to be treated may bepassed one or more times through the MG mill.

Among additional instrumentalities which can be effectively utilized inthe present invention to provide high shearing of the clay components,is the rotor and stator arrangement described in commonly assigned U.S.Pat. No. 5,160,454. The use of high shear in the present invention isnot only important in providing the benefits for the smectite which arediscussed in the foregoing patents; but moreover in the instances of thesepiolite and/or palygorskite, such high shearing acts to “debundle” theotherwise “bundled” type of structures which exist in the latterminerals. It is this debundling action which in part is believed to beinstrumental in yielding the results achieved in the present invention.

Following the high shear step, the clay components slurries may be mixedwith one another. Alternatively, the two or more clay components can beintermixed in a single slurry before the latter is subjected to the highshear step. Following such step the single slurry is intermixed with thealkyl quaternary ammonium salt, after which the slurry is dewatered, andthe alkyl quaternary ammonium-treated clay dried and ground to provide adry organoclay product. Such product is found to display unexpected andhighly desirable properties when used as a thixotrope in varioussystems. When used in the gelling of an unsaturated polyester resin, itis thus found that the composition can be stirred and dispersed directlyin an unsaturated polyester resin/monomer solution, and will providehighly satisfactory gelling properties.

The alkyl quaternary ammonium salts employed for treating the mineralclay mixtures comprise alkyl quaternary ammonium salts containing thesame or different straight- and/or branched-chain saturated and/orunsaturated alkyl groups of 1 to 22 carbon atoms and the salt moiety isselected from the group consisting of chloride, bromide, methylsulfate,nitrate, hydroxide, acetate, phosphate and mixtures thereof, preferablychloride, bromide and methylsulfate. The preferred choices of the alkylquaternary ammonium salts are dimethyl di(hydrogenated tallow) ammoniumchloride, methylbenzyl di(hydrogenated tallow) ammonium chloride,dimethylbenzyl hydrogenated tallow ammonium chloride, dimethylhydrogenated tallow-2-ethylhexylammonium methylsulfate and mixtures oftwo or more of the preferred choices. The mineral clay mixture istypically treated with 25 to 80 meq., preferably 35 to 65 meq., of thealkyl quaternary ammonium salt per 100 g of the mixture. It should beunderstood, however, that a particular combination of mineral clay (a)and mineral clay (b) may entail an amount of alkyl quaternary ammoniumsalt outside the aforementioned ranges. The requisite amount of thealkyl quaternary ammonium salt will be determined by the exchangecapacity of the selected mineral clay (a) and mineral clay (b).

The unsaturated polyester resin composition of the invention comprises asolution of an unsaturated polyester resin in a monomer which is capableof undergoing a crosslinking reaction with the resin and the mineralclay mixture described above. Suitable monomers for the unsaturatedpolyester resin are unsaturated aromatic compounds to which are bondedone or more ethylenically unsaturated radicals, such as a vinyl radical,substituted vinyl radical or an allylic radical, e.g. styrene (which ispreferred), α-methylstyrene, divinyl benzene, allyl benzene and methylmethacrylate.

The unsaturated polyester resins useful for the invention may be any ofthose known in the prior art. Suitable examples are polyesters of dienessuch as dicyclopentadiene as well as polyesters of dicarboxylic acidsand diols having a major amount of olefinic unsaturation, preferably 10to 75 olefinic groups per 100 ester groups. The olefinic unsaturation ispreferably derived from the carboxylic acid although the diol may alsobe unsaturated. Typical diols are ethylene glycol and propylene glycol.Typical unsaturated acids include maleic acid, fumaric acid and phthalicacid or anhydrides of these acids. Such polyester resins are made byconventional techniques of esterification. Generally, polyester resinshaving weight average molecular weights of about 400 to 10,000 and acidnumbers in the range of from 35 to 45 mg KOH per gram of resin areuseful for preparing the polyester compositions of the invention.

The amount of the unsaturated polyester resin in the final polyestercomposition is typically at least about 30 wt. %, based on the weight ofthe composition, with the balance being the monomer, the treated mineralclay mixture (i.e. the thixotrope), primary pigment, fillers,reinforcement fibers and additives (e.g. promoters, catalyst,dispersants, etc).

The alkyl quaternary ammonium-treated mineral clay mixture of theinvention is generally employed in the unsaturated polyester resinsystem in an amount such that the final unsaturated polyestercomposition will have a flow curve which allows application but preventsdrainage from or sag of the material from the surface to which theunsaturated polyester composition is applied. The proper thixotropicindex will depend on the intended end use of the unsaturated polyestercomposition and the manner in which the thixotropic index is measured.In general, the unsaturated polyester composition will typically have athixotropic index of at least about 1.5, preferably at least about 3.0.Generally, the amount of the alkyl quaternary ammonium-treated mineralclay mixture will be about 0.1 to 4 wt. %, based on the weight of thefinal polyester composition.

The invention will now be illustrated by examples, which are to beregarded as illustrative and not delimitative of the invention. Unlessotherwise indicated to the contrary, all parts and percentages are byweight.

EXAMPLE 1

A series of organoclay compositions were prepared from mineral claycombinations which were processed as above described, i.e. crushed,ground, slurried in water and screened, and then subjected to high shearby being passed as a dilute slurry through an MG mill, and then as asingle slurry treated with the alkyl quaternary ammonium compounds asspecified below. The resultant organoclay compositions were evaluated asthixotropes in an isophthalic unsaturated polyester resin/styrene systemhaving a 55% resin and a 45% styrene content. 1.5 g of fumed silica(used as the control thixotrope and containing no alkyl quaternaryammonium compound) was mixed with about 140 g of the resin/styrenesystem on a laboratory disperser with a tip speed of approximately 1000ft/minute for 15 minutes. A cobalt gellation promoter was added at 0.25wt. % of the resin weight. The promoter was a mixture of 8 parts ofcobalt octoate to 1 part of dimethyl aniline. The sample was then shakenon a paint shaker for 45 seconds. The above procedure was repeated with2.3 g of the organoclay compositions. Brookfield viscosities weremeasured in centipoise at one hour. The thixotropic index (“TI”) is theratio of viscosities at 10 and 100 rpm. The results are shown in Table Ibelow.

TABLE I Viscosities, cps. Mineral Clay Combinations RPM QuaternaryAmmonium Compound 1 10 100 TI 1. Fumed Silica 6500 1600 650 2.46 2. 80%sepiolite/20% hectorite 5000 1400 620 2.26 60 meq. 50% DMHTEHAMS/ 50%DMDHTAC 3. 70% palygorskite/ 1500  700 475 1.47 30% montmorillonite 60meq. DMBHTAC 4. 100% montmorillonite  500  400 400 1.00 120 meq. 75%DMDHTAC/ 25% DMBHTAC 5. 100% sepiolite 1500  800 500 1.70 60 meq. 50%DMHTEHAMS/ 50% DMDHTAC 6. 75% sepiolite/25% montmorillonite 2000  900530 1.70 60 meq. DMBHTAC meq. = milliequivalents; DMHTEHAMS = dimethylhydrogenated tallow-2-ethylhexylammonium methylsulfate; DMDHTAC =dimethyl di(hydrogenated tallow) ammonium chloride; MBDHTAC =methylbenzyl di(hydrogenated tallow) ammonium chloride; DMBHTAC =dimethylbenzyl hydrogenated tallow ammonium chloride.

EXAMPLE 2

Example 1 was repeated using an orthophthalic unsaturated polyesterresin/styrene system having a 60% resin and a 40% styrene content. Thethixotropes were loaded at 1 wt. %, based on the weight of the totalcomposition. The results are shown in Table II below.

TABLE II Viscosities, cps. Mineral Clay Combinations RPM QuaternaryAmmonium Compound 1 10 100 TI 7. 67% sepiolite/33% hectorite  7000 1350530 2.58 69 meq. DMBHTAC 8. 67% sepiolite/33% hectorite 10000 1900 6702.84 63 meq. DMBHTAC 9. Fumed Silica 11000 2300 750 3.06

EXAMPLE 3

Example 1 was repeated using a dicyclopentadiene polyester resin/styrenesystem having a 63% resin and a 37% styrene content. The thixotropeswere loaded at 1.5%, based on the weight of the total composition. Theresults are shown in Table III below.

TABLE III Viscosities, cps. Mineral Clay Combinations RPM QuaternaryAmmonium Compound 1 10 100 TI 10. 100% sepiolite 1000  400 255 1.56 30meq. 50% DMHTEHAMS/ 50% DMDHTAC 11. 70% sepiolite/30% hectorite 80001650 495 3.33 60 meq. 50% DMHTEHAMS/ 50% DMDHTAC 12. Fumed Silica 2000 650 330 1.97

EXAMPLE 4

The samples employed in this example were prepared in the followingmanner. Each sample was prepared by dispersing the crude sepiolite witha Cowles Dissolver into a slurry form of 2-10 wt. % solids, screened at100 mesh/2.5 cm to remove contaminants and thereafter subjected to onepass through the MG mill at 105,460 g/cm².

Each sample was reacted with the indicated alkyl quaternary ammoniumcompound and indicated dosage by adding the compound to the slurry withmixing at 40-80° C. The sample was thereafter dried in a blower oven at60-80° C. overnight and pulverized using a Pulvazet Mill.

Mineral clay sample 13 consisted of sepiolite treated with 45 meq. of75% MBDHTAC/25% DMDHTAC and was prepared as described above.

Mineral clay sample 14 was prepared as described in respect to mineralclay sample 13 except that it was treated with an ion exchange resin(sodium form) after passage through the MG mill but prior to treatmentwith the alkyl quaternary ammonium compound.

Mineral clay sample 15 consisted of 80% sepiolite/20% montmorillonitetreated with 55 meq. of 75% MBDHTAC/25% DMDHTAC and was prepared asdescribed above with the addition of 20% montmorillonite as a slurry atapproximately 3% solids. The 20% montmorillonite was passed through theMG mill three times at 316,395 g/cm² and added to the sepiolite slurryafter the sepiolite slurry passed through the MG mill, but prior totreatment with the alkyl quaternary ammonium compound. 50 meq. ofhydrochloric acid were added to the combined slurries prior to treatmentwith the alkyl quaternary ammonium compound.

Mineral clay sample 16 consisted of 80% sepiolite/20% hectorite treatedwith 55 meq. of 75% MBDHTAC/25% DMDHTAC and was prepared as describedabove with the addition of 20% hectorite as a slurry at approximately 3%solids. The 20% hectorite was passed through the MG mill three times at210,930 g/cm² and added to the sepiolite slurry after the sepioliteslurry passed through the MG mill, but prior to treatment with the alkylquaternary ammonium compound. 50 meq. of hydrochloric acid were added tothe combined slurries prior to treatment with the alkyl quaternaryammonium compound.

Mineral clay sample 17 was prepared in the same manner as mineral claysample 16 except that the sepiolite portion of the blend was treatedwith an ion exchange resin (sodium form) after passage through the MGmill but prior to blending and treatment with the alkyl quaternaryammonium compound.

Sample 18 was fumed silica.

Unsaturated polyester resin compositions consist of the resin, monomer,promoter/accelerator, inhibitor, thixotrope wetting agents and/orsurfactants or rheological enhancers, and the organoclay composition ofthe invention. The end user will add the catalyst to cure or crosslinkthe composition.

There are many different types of unsaturated polyester resins of whichthree types are set forth in Table IV. There are also many differenttypes of monomers. Styrene is commonly used but others such as methylmethacrylate, paramethylstyrene, vinyl toluene and others have beenused. The typical promoter is a cobalt compound such as cobalt octoateor cobalt naphthenate, but other materials such as rare earth metalcompounds may also be used. Typical accelerators are dimethylaniline anddiethylaniline. Typical inhibitors are hydroquinone andtertiarybutylcatechol. There are many types of thixotrope wettingagents/surfactants/rheological such as “Tween 20” which ispolyoxyethylene (20) sorbitan monolaurate.

The isophthalic unsaturated polyester resin system was evaluated bymixing 100 g of resin, 30 g styrene and 2.8 g mineral clay thixotropefor 15 minutes at 3800 rpm on a “Dispersamat”. 130 g of resin and 20 gstyrene were added to the mixture and mixing was continued for 2 minutesat 2200 rpm. “Tween 20” was added at 7% by weight of the thixotrope andmixed for 2 minutes at 2200 rpm. A solution containing 6% cobalt octoatewas mixed with dimethylaniline at an 8:1 ratio and was added at anamount of 0.05 wt. %, based on the weight of the entire composition, andmixed for 1 minute at 2200 rpm. The samples were cooled to roomtemperature over a 1-hour period and viscosities were measured using aBrookfield RVT viscometer at 1, 10 and 100 rpm.

The orthophthalic unsaturated polyester resin system was evaluated bymixing 150 g resin, 14 g styrene and 2.5 g mineral clay thixotrope for12 minutes at 3800 rpm on a “Dispersamat”. 62 g resin, 25 g styrene and7% by weight of the thixotrope of “Tween 20” were added to the mixtureand mixing was continued for 2 minutes at 2000 rpm. A solutioncontaining 6% cobalt octoate was mixed with dimethylaniline at an 8:1ratio and was added at an amount of 0.05 wt. %, based on the weight ofthe entire composition, and mixed for 1 minute at 2200 rpm. The sampleswere cooled to room temperature over a 1-hour period and viscositieswere measured using a Brookfield RVT viscometer at 1, 10 and 100 rpm.

The dicyclopentadiene unsaturated polyester resin system was evaluatedby mixing 150 g resin and 2.5 g mineral clay thixotrope for 12 minutesat 3800 rpm on a “Dispersamat”. Thereafter, 7% by weight of thethixotrope of “Tween 20” was added to the mixture and mixing wascontinued for 1 minute at 2000 rpm. Then 64.3 g resin, 35.7 g styreneand a solution containing 6% cobalt octoate was mixed withdimethylaniline at an 8:1 ratio and was added at an amount of 0.05 wt.%, based on the weight of the entire composition, and mixed for I minuteat 2200 rpm. The samples were cooled to room temperature over a 1-hourperiod and viscosities were measured using a Brookfield RVT viscometerat 1, 10 and 100 rpm. The results are set forth in Table IV below.

TABLE IV Isophthalic Orthophthalic Dicyclopentadiene Viscosities, cps.Viscosities, cps. Viscosities, cps. Sample 1 10 100 TI 1 10 100 TI 1 10100 TI 13  9500 1450 395 3.67  5000  950 350 2.71 4000  600 150 4.00 1410500 1550 455 3.41  6000 1100 385 2.86 3500  550 140 3.93 15  8500 1450450 3.22  5000  900 365 2.47 3500  550 140 3.93 16 18500 2650 605 4.38 9000 1550 495 3.13 8500 1150 230 5.00 17 15500 2250 560 4.02 11500 1750515 3.40 5500  800 180 4.44 18 10500 2150 660 3.26  9500 1850 625 2.962500  600 195 3.08

What is claimed is:
 1. A mineral clay composition comprising: a mineralclay mixture which has been treated with an alkyl quaternary ammoniumsalt, the mineral clay mixture comprising a mixture of palygorskite,sepiolite and a smectite, wherein the combined amount of palygorskiteand sepiolite in the mineral clay mixture comprises between about 50% toabout 95% by weight of the mineral clay mixture.
 2. The mineral claycomposition of claim 1, wherein the smectite comprises the balance byweight of the mineral clay mixture.
 3. The mineral clay composition ofclaim 1, wherein the smectite is selected from the group consisting ofhectorite, montmorillonite, bentonite, beidelite, saponite, stevensiteand mixtures thereof.
 4. The mineral clay composition of claim 3,wherein smectite comprises hectorite.
 5. The mineral clay composition ofclaim 1, wherein the alkyl quaternary ammonium salt contains the same ordifferent straight- and/or branched-chain saturated and/or unsaturatedalkyl groups of 1 to 22 carbon atoms and the salt moiety is selectedfrom the group consisting of chloride, bromide, methylsulfate, nitrate,hydroxide, acetate, phosphate and mixtures thereof.
 6. The mineral claycomposition of claim 5, wherein the alkyl quaternary ammonium salt isselected from the group consisting of dimethyl di(hydrogenated tallow)ammonium chloride, methylbenzyl di(hydrogenated tallow) ammoniumchloride, dimethylbenzyl hydrogenated tallow ammonium chloride, dimethylhydrogenated tallow-2-ethylhexylammonium methylsulfate and mixturesthereof.
 7. The mineral clay composition of claim 1, wherein the mineralclay mixture is treated with about 25 meq. to about 80 meq. of the alkylquaternary ammonium salt per 100 grams of the mineral clay mixture. 8.The mineral clay composition of claim 7, wherein the mineral claymixture is treated with about 35 meq. to about 65 meq. of the alkylquaternary ammonium salt per 100 grams of the mineral clay mixture. 9.The mineral clay composition of claim 1, wherein the mineral claycomposition in combination with an unsaturated polyester resin systemforms a thixotropic unsaturated polyester resin system, wherein thethixotropic unsaturated polyester resin/styrene system has a ThixotropicIndex from about 1.47 to about 5.0.
 10. A mineral clay compositioncomprising: a mineral clay mixture which has been treated with an alkylquaternary ammonium salt, the mineral clay mixture comprising sepioliteand a smectite, wherein the amount of sepiolite in the mineral claymixture comprises between about 50% to about 95% by weight of themineral clay mixture.
 11. The mineral clay composition of claim 10,wherein the smectite comprises the balance by weight of the mineral claymixture.
 12. The mineral clay composition of claim 10, wherein thesmectite is selected from the group consisting of hectorite,montmorillonite, bentonite, beidelite, saponite, stevensite and mixturesthereof.
 13. The mineral clay composition of claim 12, wherein thesmectite comprises hectorite.
 14. The mineral clay composition of claim10, wherein the alkyl quaternary ammonium salt contains the same ordifferent straight- and/or branched-chain saturated and/or unsaturatedalkyl groups of 1 to 22 carbon atoms and the salt moiety is selectedfrom the group consisting of chloride, bromide, methylsulfate, nitrate,hydroxide, acetate, phosphate and mixtures thereof.
 15. The mineral claycomposition of claim 14, wherein the alkyl quaternary ammonium salt isselected from the group consisting of dimethyl di(hydrogenated tallow)ammonium chloride, methylbenzyl di(hydrogenated tallow) ammoniumchloride, dimethylbenzyl hydrogenated tallow ammonium chloride, dimethylhydrogenated tallow-2-ethylhexylammonium methylsulfate and mixturesthereof.
 16. The mineral clay composition of claim 10, wherein themineral clay mixture is treated with about 25 meq. to about 80 meq. ofthe alkyl quaternary ammonium salt per 100 grams of the mineral claymixture.
 17. The mineral clay composition of claim 16, wherein themineral clay mixture is treated with about 35 meq. to about 65 meq. ofthe alkyl quaternary ammonium salt per 100 grams of the mineral claymixture.
 18. The mineral clay composition of claim 10, wherein themineral clay composition in combination with an unsaturatedpolyester/styrene resin system forms a thixotropic unsaturated polyesterresin system, wherein the thixotropic unsaturated polyester resin systemhas a Thixotropic Index from about 1.47 to about 5.0.
 19. A mineral claycomprising: a mineral clay mixture which has been treated with an alkylquaternary ammonium salt, the mineral clay mixture comprisingpalygorskite and a smectite, wherein the amount of palygorskite in themineral clay mixture comprises between about 50% to about 95% by weightof the mineral clay mixture.
 20. The mineral clay composition of claim19, wherein the smectite comprises the balance by weight of the mineralclay mixture.
 21. The mineral clay composition of claim 19, wherein thesmectite is selected from the group consisting of hectorite,montmorillonite, bentonite, beidelite, saponite, stevensite and mixturesthereof.
 22. The mineral clay composition of claim 21, wherein thesmectite comprises hectorite.
 23. The mineral clay composition of claim19, wherein the alkyl quaternary ammonium salt contains the same ordifferent straight- and/or branched-chain saturated and/or unsaturatedalkyl groups of 1 to 22 carbon atoms and the salt moiety is selectedfrom the group consisting of chloride, bromide, methylsulfate, nitrate,hydroxide, acetate, phosphate and mixtures thereof.
 24. The mineral claycomposition of claim 23, wherein the alkyl quaternary ammonium salt isselected from the group consisting of dimethyl di(hydrogenated tallow)ammonium chloride, methylbenzyl di(hydrogenated tallow) ammoniumchloride, dimethylbenzyl hydrogenated tallow ammonium chloride, dimethylhydrogenated tallow-2-ethylhexylammonium methylsulfate and mixturesthereof.
 25. The mineral clay composition of claim 19, wherein themineral clay mixture is treated with about 25 to about 80 meq. of thealkyl quaternary ammonium salt per 100 grams of the mineral claymixture.
 26. The mineral clay composition of claim 25, wherein themineral clay mixture is treated with about 35 meq. to about 65 meq. ofthe alkyl quaternary ammonium salt per 100 grams or the mineral claymixture.
 27. The mineral clay composition of claim 19, wherein themineral clay composition in combination with an unsaturated polyesterresin system forms a thixotropic unsaturated polyester resin system,wherein the thixotropic unsaturated polyester resin/styrene system has aThixotropic Index from about 1.47 to about 5.0.